Pack advancer for sheet feeding mechanism



Sept. 19, 1944. F CU I 2,358,560

PACK ADVANCER FOR SHEET FEEDING MECHANISM Original Filed Feb. 8, 1941 3 Sheets-Sheet 1 INVENTOR. BY wafct m/Jf,

QM, rid afiawb Sept. 19, 1944. -n5 I 2,358,560

PACK ADVANGER FOR SHEET FEEDING MECHANISM Original Filed Feb. 8, 1941 5 Sheets-Sheet 2 Sept. 19, 1944. F. E. CURTIS 2,358,560

PACK ADVANCER FOR SHEET FEEDING MECHANISM Original Filed Feb. 8, 1941 3 Sheets-Sheet 3 57 422 .50 jt F U 5.8 F=

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| 70 +1; 56 E I F 7 INVENTOR. BY E. War/(vi, Fe/m V flfifiam,

Patented Sept. 19, 1944 PACK ADVANCER FOR- SHEET FEEDING MECHANISM Franklin E. Curtis, Wickliffe, Ohio, assignor to Addressograph-Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Original application February 8, 1941, Serial No.

378,034. Divided and this 11, 1941, Serial No. 414,633

3 Claims.

This invention is a division of my copending application filed February 8, 1941, and assigned Serial No. 378,034. Th present invention relates to improvements in sheet. feeding mechanisms, and is especially concerned with improvements in and relating to a pack advancer for a sheet feeding mechanism.

The general object of the present invention is to provide an improved pack advancing mechanism which will advance a pack of sheets from time to time and thus maintain the top of the stack or pile substantially at a predetermined height despite the withdrawal of sheets from the top of the stack by a sheet feeding mechanism.

Amore specific object of this invention is to provide a pack advancing mechanism which will automatically advance a pack of sheets to maintain the top of the stack at a predetermined height, the operation of the mechanism being controlled by the height of the stack.

A further object of this invention i to provide a pack advancing mechanism which will b extremely rugged and yet which will be responsive to minor variations in the height of the pack to the end that the top of the stack may be maintained at a predetermined height with a high degree of accuracy to the end that the pack advancer may b used with a relatively high speed sheet feeding mechanism and with relatively thin sheets.

. Other objects and features of this invention will become more apparent from the following description, reference being had to the accompanying drawings in which there is illustrated a preferred embodiment of the invention. The essential features of the invention will be summarized in the claims.

In the drawings, Fig. -1 is a side elevation of a duplicating machine, comprising the pack advancing mechanism of the present invention, and associated sheet feeding and printing mechanisms mounted on a common support, the operating mechanisms being housed in a cabinet enclosing the support, certain parts of the cabinet being broken away to illustrate certain power operating mechanism; Fig. 2 is an enlarged side elevation of the pack advancing mechanism with the cover plates removed and certain other parts broken away to more clearly illustrate the mechanism; Figs. 3 and 4 are details on an enlarged scale of the ratchet wheel operatin mechanism used in connection with the raising of a stack support; Fig. 5 is a top plan view of the parts shown in Fig. 2; and Fig. 6 is a sectional elevation application October of the control mechanism coacting with the top of 55 the stack of sheets, the plane of the section being indicated by the lines 6-6 on Fig. 5.

Referring now to the drawings, wherein there is illustrated a preferred form of the invention, and particularly to Fig, 1, there is shown a frame l0 enclosed bya cabinet I l which is provided with doors l2 to permit access to the interior thereof. Mounted on top of the cabinet, at the left hand end as viewed in Fig. 1, is a printing machine M. The pack advancer with which the present invention is particularly concerned is mounted at the right hand end of the cabinet. The pack advancer l5 supports a stack of work sheets W to enable them to be fed one ata time to the printing machine. Atop the cabinet adjacent the pack advancer, is a sheet separating device l6 which separates the top sheet from the pile and. progresses it to the printing mechanism.

The printing machine shown in the drawings is a planographic duplicatin machine. It is supported on a pair of cross bars 25 of the frame l0, and comprises a pattern roll 26, an oifset roll 21, a platen roll 28, and an inking mechanism (not shown). The various roll of the printing machine are journalled in suitable side plates, one of which is shown at 29 in Fig. 1.

The printing mechanism is driven by a motor 30 mounted on a bracket 3| disposed within the cabinet. Suitable driving elements, such as the beltsand pulleys 32 interconnect the motor 30 with a gear 33, which meshes with a gear 34 carried by the offset roll 21, thu driving the latter. The pattern roll 26 is driven by frictional engagement with the offset roll in the usual manner. The platen roll is driven by a gear 35 carried thereby and which meshes with the gear 34.

The sheet feeding mechanism comprises in general a vacuum type feeding foot l6a which is positioned above the uppermost sheet on the stack and is actuated to remove such sheet from the top of the stack and feed it to a delivery mechanism (not shown) which delivers the sheet to the printing mechanism. A suitable vacuum pump 20, driven by a motor 2| provides the required vacuum for the'feeding foot. The foot, however, as well as the delivery mechanism is preferably operated from and in timed relationship with the printing machine. This feeding mechanism forms the subject matter of my copenin application heretofore referred to, therefore reference may be had to such application for a more complete description and disclosure of such mecha- I11Sm.

The pack advancing mechanism IS with which the present invention is concerned includes a table gearing 12.

45 which supports a pile or stack of sheets W to be fed. This table is best illustrated in Figs. 1, 2

A spring 54 interconnected between the bar and the pin normally maintains the left hand end and 3. As there shown, the stack of sheets W is placed on a table 45, with its forward corners seated in vertically extending guides 44 which are adjustable transversely of frame members 45. The P per table 45 is slidably mounted for vertical movement in the frame I0, the arrangement being such that the table may be raised at periodic intervals to maintain the uppermost sheet in the the sides of the table 45 and engage the flanges of vertically extending channels 48 carried by the frame I0, thus guiding the table for vertical movement.

The table 45 is supported by a pair of chains, v

one of which is shown at 50 in Fig. 2. These chains are attached to respective side flanges 45 of the table 45, as at and extend upward to respective sprocket Wheels 52 and thence downward. A counterweight 55 is secured to the depending free end of each chain. The sprocket wheels 52 are secured to across shaft 55 which is journalled in the side plates 51 supported by the frame I0. This shaft extends through the near side plate 51 (Fig. 2) and carries a worm gear 58 which meshes with a worm 59, supported in a bearing bracket 53 carried by the frame plate 51. The coacting worm and worm gear unit serve as a brake to restrain the movement of the table and retain it in an adjusted position.

Positioning of the table to receive a stack of sheets or to bring the top of the stack to the desired initial elevation, is accomplished by the operation of a manually operable handle or crank 50.. This handle is rotatably mounted on the outer end of the shaft 55', which as indicated in Fig. 1, extends outward to the exterior ofthe cabinet. The handle 50 is also axially slidable on the shaft 55 to permit it to be brought into clutching engagement with the hub of a gear 52. The gear 52 is rotatable on the shaft 55 and meshes with a gear 53 mounted on a stub shaft 54 carried by the frame plate 51. Also mounted on the shaft 54 and drivingly secured to the gear 53 is a bevel pinion 55 which meshes with a similar bevel pinion 55 secured to the worm 59 in any well-known manner, thus completing a manual drive to the worm gear, to raise or lower the table 45.

The paper table 45 is periodically raised by a power operated mechanism, the effective operation of which is controlled by the height of the stack. As shown in Figs. 2 and 6, a. bail is pivotally mounted on the side plates 51 and extends therebetween in position to engage the uppermost sheet of the stack.

To permit withdrawal of the top sheet from the stack, the ball 10 is periodically moved out of contact with the sheets by a system of links actuated by the printing machine. Referring to Fig. 1, it will be seen that the printing machine is provided with a crank 1| which is rotated by the platen roll gear 35, through the medium of This crank is connected by a link 13 with the upper end of a lever 14, pivoted as at 15, to a side plate 51. A bar is connected to the lever 14 by a pin and slot connection 11.

of the slot (Fig. 2) in engagement with the coacting pin. At its right hand end the bar 15 carries a pin 18 which projects through an opening 19 in the side plate 51 and is connected with an arm 80 journalled on the bail pivot 8|.

A resilient connection is provided between the bail 10 and the arm 80. As shown in Fig. 6, this connection comprises a threaded sleeve 82, which is resiliently positioned on the arm 80 by a spring 83 and a threaded stud 84 which is carried by the sleeve and pivotally connected to the ball 10, as at 85. The bail 10 comprises, as indicated in Fig. 8, a bar 85 which extends transversely across the stack and which is provided with slotted arms 81. These arms are adjustably secured to respective bell cranks 88, the latter being pivoted to respective side plates 51, as at 8|.

Whenever the height of the stack falls below a predetermined level, the bail moves downward until a pin 90, carried by the arm 15 engages the upper end of a latch 9|. The latch 9| is best shown in Figs. 2 and 6, and is pivoted intermediate its ends, as at 92, to a side plate 51. A deficiency in the height of the stack causes the pin 90 to engage and swing the latch in a clockwise direction (Fig. 2), against the action of a spring 93. This draws the lower end of the latch 9| out of engagement with an abutment 94 (Figs. 3 and 4) of a pawl carrier 95. The carrier is pivoted on a ratchet wheel shaft 95 upon which a ratchet wheel 91 is rotatably mounted. The withdrawal of the latch 9| permits a spring I05 to rock the pawl carrier about the shaft 96 in a clockwise direction from the position shown in Fig. 4 into contact with a stop 98, as shown in Fig. 3. In this position, a pawl 99, pivotally connected to the carrier, as at I00, is in engagement with the ratchet wheel 91 and is in position I to impart an advancing movement to such wheel consequent upon a counterclockwise movement of the pawl carrier.

The ratchet wheel 91 is advanced by movement of the lever 14. As shown in Figs. 1 and 2, a bar IOI is pivotally secured between the lower end of the lever 14 and a pivoted supporting arm I02. The pivotal connection between the arm I02 and the bar IOI comprises a pin I03 (Figs. 3 and 4) which, as the bar moves to the right engages an abutment I04 on the pawl carrier 95, swinging the carrier to the position shown in Fig. 4, and advancing the ratchet wheel a distance of one tooth. The movement of the ratchet ,wheel is imparted to the worm 58 by a gear I05 (Fig. 2) drivingly secured to the ratchet wheel 91 and in constant engagement with the. gear 52 heretofore described, thus actuating. the table raising mechanism.

As long as the top .of the stack of sheets W remains below the desired elevation, the latch 9| will be retained in its unlatched position and the ratchet wheel operating mechanism will continue to function in repeating cycles of operation. When the stack'reaches the desired elevation the spring 93 will draw the latch into a latching position whereupon it will reengage the abutment 94 and stop the pawl carrier in the position shown in Fig. 4. When the height of the pile drops a predetermined amount, the latch 9| will again be moved by the operation of the ball 10, and the pile again raised. Thus, the top sheet of the stack for all practical purposes is maintained at a constant elevation.

To free the ratchet wheel from the power oper ated mechanism when the crank 60 is actuated to manually position the paper 45, a pawl release lever 40 is pivotally mounted, as at 4|, to the near frame plate 51, as shown in Fig. 2. When the crank 60 is operated, the lever 40 is manually turned clockwise causing the end 42 thereof to engage a pin 49 on the pawl 99 moving it out of engagement with the ratchet wheel 91. A spring, now shown, normally maintains the lever 40 in an idle position.

The rearmost end of the stack of sheets is guided by a pair of adjustable guides I20. These guides are adjustably secured to a. cross bar l2l, carried by bars I22 which are adjustably mounted on respective frame plates 51. The forward projecting portions of the guides thus embrace the stack of sheets W.

From the foregoing description it will be seen that I have provided a highly efficient table raising mechanism which may be actuated to raise the stack supporting table a small amount during each cycle of operation of the printing machine. However, the arrangement of the mechanism is such that it is dependent upon the height of the stack for its operation. It will be noted that the ratchet mechanism including the feed pawl, the ratchet, and the mechanism connecting the ratchet with the table, is normally inactive and is operated only when a latch is withdrawn due to a decrease in the height of the stack. This arrangement greatly reduces the wear on the moving parts of the mechanism.

I claim:

1. A pack advancer for a sheet feeding mechanism comprising a pack supporting table mounted for-vertical movement, mechanism for periodically raising the table including an actuating ratchet wheel, an oscillatable pawl-carrying frame having a pawl to drivesaid ratchet wheel, means normally acting to move said frame to a starting position wherein said pawl is at the beginning of its ratchet advancing stroke, a rockable arm adapted to move said pawl-carrying frame in the pawl-advancing direction, a periodically oscillated lever, a link pivotally connected to said lever and to said arm to contact and move said frame in a pawl-advancing direction, a latch coacting with said pawl-carrying frame, means normally acting on'said latch to position the latch to retain said pawl-carrying frame at the end of its advancing stroke, a member pivotally connected to the frame and having means adapted to rest on the top of the pack, a link having one end connected to said member and having its other end resiliently connected to said lever to cause said member to coact with the top of the pack, and means carried by said last named link to trip said latch whenever the height of said pack falls below a predetermined elevation.

2. A pack advancer for a sheet feeding mechanism comprising a pack supporting table slidably mounted for vertical movement, a rotatable sprocket wheel shaft, a pair of spaced sprocket wheels on said shaft, chains looped over respective sprocket wheels and secured to said table, a worm wheel drivingly connected to said shaft, a worm coacting with said worm wheel, a ratchet wheel, gearing connecting said ratchet wheel with said worm, a pawl-carrying frame, rockable about the axis of said ratchet wheel, a spring normally acting to move said frame to a starting position wherein said pawl is at the beginning of its ratchet advancing stroke, an arm rockable about the axis of said ratchet wheel and adapted to move said pawl carrying frame in the pawl said arm to contact and move said frame in a pawl advancing direction, a latch coacting with said pawl carrying frame, a spring normally acting on said latch to position the latch to retain said pawl carrying frame at the end of its advancing stroke, a bail pivotally connected to the frame and having means adapted to rest on the top of the pack, a link having one end adjustably connected to said bail and having its other end resiliently connected to said intermediately pivoted lever to cause said bail to coact with the top of the pack periodically, and means carried by said last named link to trip said latch whenever the height of said pack falls below a predetermined elevation.

3. A pack advancer for a sheet feeding mechanism comprising a. pack supporting-table, mechanism for periodically raising the table including an actuating ratchet wheel, an oscillatable pawl carrier coacting with the ratchet wheel to drive the same, mechanism for operating the pawl carrier, a la ch to restrain movement of the pawl carrier, a feeler adapted to coact with the top of the pack, a reciprocating member, means interconnecting the said member and said feeler for moving said feeler into and out of contact with the top of the pack, said means comprising a pivoted lever connected to be rocked by said member, a pivoted bell crank, said feeler being supported by one arm of said bell crank, an adjustable connection between said lever and the other arm of said bell crank whereby the position of said feeler relative to the top of the pack may be varied, means whereby the distance between the feeler and the pivot of the bell crank may be altered to increase or decrease the length of strok of said feeler, and means responsive to a pre-determined position of said lever to release said latch.

FRANKLIN E. CURTIS. 

